一种跳相发射分集技术的差分方案

将差分编码方案引入到跳相发射分集系统中,提出了跳相差分空时编码(PHDSTBC)方案,该方案有效地改善了整个系统中的差错性能和时延。同时,伪随机的相位跳变大大增强了系统的保密性及干扰对抗性,提高了系统抗突发错误和深度衰落的能力。仿真结果表明,在准静态Rayleigh信道下,误码率为10-3时,新方案相比TarokhJafarkhani差分空时方案(TJDSTBC)性能有1.5dB的信噪比增益。     

未来网络技术与发展趋势综述

对面向2030的未来网络领域的发展趋势进行了综述。首先,介绍了网络体系架构和试验设施领域的研究进展;其次,从网络控制与编排、网络深度可编程、网络确定性服务、网络计算存储一体化、网络与人工智能、网络与区块链、智能安全网络、网络空天地海一体化8个方面阐述了当前热点网络技术的背景、进展和主要成果;最后,分析了面向2030的未来网络发展趋势,预计到2030年未来网络将支撑万亿级、人机物、全时空、安全、智能的连接与服务。希望能为未来网络相关领域的研究提供参考和帮助。     

一种在软件定义网络中的新型无泛洪服务发现机制(英)

The low-cost,self-configuration capability and "plug-and-play" feature of Ethernet establishes its dominant position in the local area networks(LAN).However,it is hard to extend to large scale because of the legacy broadcast-based service discovery mechanism.Therefore,to solve this problem,a new split network architecture named Software-Defined Networking(SDN) is introduced in this paper,and a novel floodless service discovery mechanism(FSDM)for SDN is designed.For the FSDM,the widespread broadcast messages for Dynamic Host Configuration Protocol(DHCP) and Address Resolution Protocol(ARP) are considered especially,respectively.Then the DHCP relay and ARP proxy are proposed to handle DHCP broadcast messages and ARP broadcast messages,respectively.The proposed FSDM in this paper can eliminate flooding completely,reserve the autoconfiguration characteristics.Particularly,there is no need to change the existing hardware,software and protocols of hosts for the proposed scheme.Finally,the simulation results are demonstrated to show that our proposed model allows redundant links existed in network and has the property of scalability,which can significantly reduce network traffic in data plane and control traffic in control plane,and decrease the overhead of control plane.     

基于拓扑感知的虚网映射算法框架（英文）

The virtual network embedding/mapping problem is an important issue in network virtualization in Software-Defined Networking(SDN).It is mainly concerned with mapping virtual network requests,which could be a set of SDN flows,onto a shared substrate network automatically and efficiently.Previous researches mainly focus on developing heuristic algorithms for general topology virtual network.In practice however,the virtual network is usually generated with specific topology for specific purpose.Thus,it is a challenge to optimize the heuristic algorithms with these topology information.In order to deal with this problem,we propose a topology-cognitive algorithm framework,which is composed of a guiding principle for topology algorithm developing and a compound algorithm.The compound algorithm is composed of several subalgorithms,which are optimized for specific topologies.We develop star,tree,and ring topology algorithms as examples,other subalgorithms can be easily achieved following the same framework.The simulation results show that the topology-cognitive algorithm framework is effective in developing new topology algorithms,and the developed compound algorithm greatly enhances the performance of the Revenue/Cost(R/C) ratio and the Runtime than traditional heuristic algorithms for multi-topology virtual network embedding problem.     

全业务运营商的FMC策略探讨

文章从固定移动网络融合(FMC)的需求背景入手,深入分析了FMC技术的本质内涵。针对国外主流运营商的经验,回顾总结了前期发展FMC的主要产品及运营策略,并结合相应的成功经验,给出了固定移动融合分步骤、分层次的整体实施策略,为国内全业务运营商未来FMC的部署与演进提出了发展建议。     

基于超声波测距的多功能面积/体积测量仪的设计

超声波测距是一种性能良好的测距方式,已经广泛应用于倒车雷达、工地以及一些工业控制现场。文章基于超声波测距原理,设计了一种具有温度补偿的可测量室温、长度、面积、柱体体积的测量仪器,并给出了详细的设计方案及系统电路。     

管道输水灌溉在江西农田水利的应用前景分析

结合江西实际,指出在我省实施管道输水灌溉是高效节水灌溉的重要组成部分.通过分析江西省实施管道输水灌溉的必要性,阐述管道输水灌溉优势,提出了管道输水灌溉实施保障措施,阐明管道输水灌溉在我省有着广阔的应用前景,大力推广管道输水灌溉是完成我省"十三五"规划高效节水灌溉任务的重要举措.     

都市社区大众体育健身活动现状调查及分析——以成都市芳草辖区为例

都市社区群众性的体育活动,是我国体育事业的重要组成部分,它关系到全国人民群众的身心健康和幸福快乐的生活。随着群众性的体育事业的发展,一些城市以社区居民为主体、以社区环境为依托,组织了丰富多彩、人民群众喜闻乐见的体育活动,     

粘棉交织物的阳离子改性及染色工艺

为提高活性染料上染率,采用阳离子改性剂CR2000对粘棉交织物进行改性处理,优化的改性工艺条件为:改性剂CR2000质量浓度20 g/L,NaOH质量浓度8 g/L,改性时间60 min,改性温度80℃,浴比1∶10.活性大红RGB的染色优化工艺为:pH值7,染色时间60 min,染色温度80℃,浴比1∶10.改性粘棉交织物活性染色得色量高、染色牢度好,染料利用率大大提高,染色残液的COD值大幅降低.     

级联多电平电压质量调节装置的多目标控制

研究了H桥级联5电平结构的电压质量调节装置,在分析装置工作原理的基础上,对系统中出现的典型电压质量问题提出了多目标控制策略,能综合解决电压暂降、谐波等问题。同时,在负荷侧发生短路故障时,还能实现限制短路电流的控制目标。基于PSCAD/EMTDC仿真软件建立了多目标电压质量调节器的仿真模型,仿真结果验证了所提出的主电路拓扑和控制策略的正确性和有效性。